The device appeared to be inert, but the school contacted the Police Department, which sent officers to the neighboring campuses on 17th Street, Lt. Russell Reinhart said. The Orange County Sheriff's Department bomb squad also arrived to examine the device.

Reinhart said the grenade still had an active firing pin, but the explosive material had been removed. The student, though, had taped the bottom of the grenade back on, which made it appear to still be active.

The grenade, he said, was apparently a family heirloom. School administrators found out about the device after a student notified a teacher, Reinhart said.